21060087 has 4 divisors (see below), whose sum is σ = 28080120. Its totient is φ = 14040056.

The previous prime is 21060079. The next prime is 21060097. The reversal of 21060087 is 78006012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21060087 - 2³ = 21060079 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21060077) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3510012 + ... + 3510017.

It is an arithmetic number, because the mean of its divisors is an integer number (7020030).

Almost surely, 2^21060087 is an apocalyptic number.

21060087 is a deficient number, since it is larger than the sum of its proper divisors (7020033).

21060087 is an equidigital number, since it uses as much as digits as its factorization.

21060087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7020032.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 21060087 is about 4589.1270411702. The cubic root of 21060087 is about 276.1553027453.

Adding to 21060087 its reverse (78006012), we get a palindrome (99066099).

The spelling of 21060087 in words is "twenty-one million, sixty thousand, eighty-seven".